Analysis of the essential oil composition of three cultivated Nepeta species from Iran.

Essential oils (EOs) of three Iranian cultivated Nepeta species were investigated. The oils were obtained by hydrodistillation of air-dried plant materials at full flowering stage and analyzed by gas chromatography (GC) and gas chromatography coupled to mass spectroscopy (GC/MS). In total, 89 compounds were detected. In over 2 years, a number of constituents were identified in the EO of Nepeta binaloudensis first and second years (26 and 37, respectively), Nepeta cataria (25 and 32, respectively), and Nepeta assurgens (45 and 50, respectively). In the oils of N. binaloudensis, 4a-α,7-α,7a-α-nepetalactone (NL) 59.7% and 1,8-cineole (19.6%) during the first and second years, respectively, were the main constituents. The main components of N. cataria were 4a-α,7-α,7a-β-NL (72.8%) and 4a-α,7-β,7a-α-NL (73.9%) during the first and second years, respectively, and 4a-α,7-α,7a-α-NL (55.5%) and 1,8-cineole (24.1%) during the first and second years, respectively, were the main constituents of N. assurgens. The results showed that NLs isomers and 1,8-cineole were the main components of the oils of three cultivated Nepeta species.